We know that a marathon is 26.2 miles, so we can set up a proportion to solve for the time it would take her to run the entire marathon:
[tex] \frac{2miles}{16minutes} =\frac{26.2miles}{x} [/tex]
Then solve for x by cross multiplying:
[tex] 2x=419.2 [/tex]
[tex] x=209.6minutes [/tex]
So now we know it will take Karla 209.6 minutes to run the entire marathon, or, in hours, 3.49 hours.